Abstract

A description is given of the method for the retrieval of atmospheric column-averaged dry-air mole fractions of carbon dioxide (XCO2) from the data of IKFS-2 infrared Fourier spectrometer on board the Meteor-M Russian meteorological satellites. The method is based on estimating XCO2 using a second-order regression, whose predictors are the effective spectral optical depths of the atmosphere in the infrared region of 8–14 \(\mu\)m. The optical depth is determined using spectral intensities of outgoing radiation measured by the IKFS-2 as well as the calculated intensities of the Earth’s surface or cloud top simulated as a gray body with temperature \(T_\mathrm{s}\). The temperature \(T_\mathrm{s}\) is retrieved from IKFS-2 measurements within the atmospheric microwindow at the wave number equal to 900.1 cm\(^{-1}\). The reference XCO₂ values for constructing the regression were the results of contact CO₂ measurements on the tall tower at the ZOTTO international observatory (Central Siberia) and at the NOAA observatory on the Mauna Loa volcano (Hawaii) in 2015–2016. The methodology was validated by comparing the XCO2 retrieved from Meteor-M No. 2 IKFS-2 measurements with parallel measurements over Siberia by the OCO and CrIS satellite spectrometers on board the OCO-2 and NOAA-20 satellites (USA). The maximum discrepancies in the daily estimates of the spatially averaged XCO2 during October 9–19, 2021 derived from the IKFS-2 data do not exceed 2.3 ppm versus the OCO data and 5 ppm versus the CrIS data.

中文翻译：

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从 Meteor-M 2 号卫星数据中检索俄罗斯上空的总二氧化碳柱

摘要

介绍了利用俄罗斯气象卫星 Meteor-M 上的 IKFS-2 红外傅里叶光谱仪数据反演大气柱平均干空气二氧化碳摩尔分数 (XCO2) 的方法。该方法基于使用二阶回归估计 XCO2，其预测因子是 8-14  \(\mu\) m 红外区域中大气的有效光谱光学深度。使用由 IKFS-2 测量的出射辐射的光谱强度以及模拟为具有温度 \(T_\mathrm{s}\)的灰体的地球表面或云顶的计算强度来确定光学深度。温度\(T_\mathrm{s}\)在波数等于 900.1 cm \(^{-1}\) 的大气微窗口内从 IKFS-2 测量中检索到。构建回归的参考 XCO ₂ 值是接触 CO _2的结果 2015-2016 年在 ZOTTO 国际天文台（中西伯利亚）和 NOAA 天文台对莫纳罗亚火山（夏威夷）的高塔上进行的测量。通过比较从 Meteor-M No. 2 IKFS-2 测量中检索到的 XCO2 与 OCO-2 和 NOAA-20 卫星（美国）上的 OCO 和 CrIS 卫星光谱仪在西伯利亚上空的平行测量，验证了该方法。根据 IKFS-2 数据得出的 2021 年 10 月 9 日至 19 日期间空间平均 XCO2 的每日估计的最大差异与 OCO 数据相比不超过 2.3 ppm，与 CrIS 数据相比不超过 5 ppm。